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Updated: Jul 18, 2026

Quantitative Analysis of Cell Edge Dynamics during Cell Spreading
Published on: May 22, 2021
Two distinct actin networks drive the protrusion of migrating cells
A Ponti1, M Machacek, S L Gupton
1Department of Cell Biology, Scripps Research Institute (TSRI), La Jolla, CA 92037, USA.
Abstract:
Cell migration initiates by extension of the actin cytoskeleton at the leading edge. Computational analysis of fluorescent speckle microscopy movies of migrating epithelial cells revealed this process is mediated by two spatially colocalized but kinematically, kinetically, molecularly, and functionally distinct actin networks. A lamellipodium network assembled at the leading edge but completely disassembled within 1 to 3 micrometers. It was weakly coupled to the rest of the cytoskeleton and promoted the random protrusion and retraction of the leading edge. Productive cell advance was a function of the second colocalized network, the lamella, where actomyosin contraction was integrated with substrate adhesion.
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